The present disclosure relates to the manufacturing of recordable media, and more specifically to quality control methods for the storage media substrates.
Manufacturing processes for recordable media may include substrate materials of various types, upon which layers of magnetic or other material are added through sputtering or other deposition processes. Moreover, at various times a manufacturing facility may produce recordable media using different substrate materials, perhaps even using common equipment to produce the media in separate batches or processes. Following the material deposition onto the substrates, however, the different substrate materials may be difficult or impossible to visually or optically distinguish.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation. The illustrations referred to here should not be understood as being drawn to scale unless specifically noted. Also, the drawings are often simplified and details or components omitted for clarity of presentation and explanation. The drawings and discussion serve to explain principles discussed below, where like designations denote like elements.